This is absolutely the craziest thing I've ever heard of!! I recently bought an iPAQ 6315 off eBay, and after connecting to a hotspot here in town, I could not get the wifi to shut off. I was afraid I had somehow messed up the phone and wasted the money I spent, so I tried googling every imaginable thing, and finally came across this site. I tried smacking it lightly twice, and then smacked a little harder. Voila! I'm now able to turn off the wifi. Thanks for the hint!